A Spacecraft Fault Tolerant Control Method Based on Angular Velocity Observer

Abstract

The invention relates to a spacecraft fault tolerant control method based on an angular speed observer. The method comprises a step of considering an actuator fault and external disturbance borne by a spacecraft, and establishing a spacecraft attitude control system dynamics and kinematics model, a step of designing a finite time observer to estimate the attitude angular velocity information of a spacecraft, and a step of constructing a robust controller based on the obtained angular velocity information, and at the same time considering control amount input saturation and designing an auxiliary system such that the spacecraft has robustness for the actuator fault without angular velocity information. According to the method, the stability of an attitude control system is ensured when an on-orbit working spacecraft has the actuator fault and even the attitude angular velocity information is unknown, and the method has high control precision, high fault tolerance ability and robustness to external disturbance.

Description

technical field [0001] The invention relates to a spacecraft control method based on an observer and attitude fault-tolerant control, which is mainly applied to the attitude control of an actuator failure when the spacecraft is in orbit and is subject to external disturbance moments from space and amplitude saturation constraints of the actuator The system, and the attitude angular velocity observer is used to overcome the defects of the attitude sensor, which belongs to the technical field of spacecraft control. Background technique [0002] The status of spacecraft in the space field is becoming more and more important, and its performance and technology are also improving accordingly. The spacecraft control system is one of the most important subsystems in the entire aerospace system. Its performance requirements are directly related to the execution level of space missions. Its safety indicators are very critical and its reliability requirements are getting higher and hi...

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Problems solved by technology

[0005] The problem solved by the technology of the present invention is: due to the possible failure of the actuator in some spacecraft attitude control systems and the saturation limitation of the control input, the attitude sensor of the spacecraft has the problem of noise or failure of the angular velocity information. For the problem affected by the external disturbance moment, the present invention provides a spacecraft fault-tolerant control method based on an angular velocity observer, which is a compound control method with angular velocity information without an attitude sensor and fault-tolerant capability, and a finite-time observer is designed Estimate the angular velocity information, so as to solve the defects of the attitude sensor of the spacecraft system, such as noise, and introduce a robust controller and auxiliary system to solve the problem that the actuator fails when the spacecraft is working in orbit and the control input is saturated and limited. The problem of the influence of external disturbance moment ensures the fault tolerance and robustness of the system

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